抄録
Our new project is to detect minimal brain injury in the shaken-baby syndrome. We will take a rat model that was established by Ueda et al (Neuroscience Letters, 385 82-86 2005). A high-spatial resolution image and a diffusion analysis can be useful to detect and follow pathological changes in the brain. It is reasonable to take a higher field to get a better image of small brains of neonatal, infantile, and juvenile rats that are similar size to mouse. In order to establish a basic system in vertical high-field MR micro-imaging system, we had made a probe with the stereotaxic coordinates for mice inside a gradient system. A set of the conventional fixation devices (a bite bar and a pair of ear bars) was installed in an acrylic tube. The position of the bite bar can be adjusted to the level position. 1% enflurane in a gas mixture of 36% O2-2%CO2-62% NO delivered through the tracheal canula by artificial ventilator. The body temperature was kept in adequate range by a hot water circuit, and the temperature was monitored by fluorescence thermometer. ECG was also monitored by PowerLab. Using this probe, we can get reasonable quality of gradient-echo image, spin-echo diffusion image, and multi-slice multi-spin-echo image in 100 μm pixel resolution with a slice thickness of 0.5 mm. Vital conditions of mice kept constant for 4 hours and longer. We are now trying to detect a minimal hemorrhage in the infant rat brain that was shaken by a shaking machine. [J Physiol Sci. 2006;56 Suppl:S213]
